Fuel Tank Inlet Device

ABSTRACT

An inlet device ( 1 ) for a tank, the device comprising an attachment portion ( 2 ) adapted to allow the device to be secured to a tank or filler neck thereof and an inlet body portion ( 5 ) for the receipt of liquid, the inlet body portion comprising an inlet ( 12 ) for the ingress of liquid and an outlet for the egress of liquid into a tank, the inlet body portion comprising a wall portion ( 7 ) depending from a first end of the device at or in the vicinity of the inlet to an end portion ( 9 ) associated with a second end of the device, the end portion having an inner surface ( 9   a ) for the receipt of liquid and an outer surface ( 9   b ), the outlet being provided by a plurality of bores ( 10   a - e ) in a part ( 21 ) of the wall portion associated with the end portion and the inner surface of the end portion being shaped so as to direct liquid towards one or more of said bores, the inner surface of the end portion being provided with a surface of revolution for directing liquid towards one or more of said bores, one or more of said bores extending from a bore inlet ( 18 ) for the receipt of liquid to a bore outlet ( 19 ) for the egress of liquid, wherein the bore outlet has a greater cross-sectional area than the corresponding bore inlet

The present invention relates to fuel tank inlet devices, particularly,but not exclusively, those fuel inlet devices that inhibit the theft offuel from a fuel tank fitted with such a device.

Fuel tank inlet devices are known that inhibit the theft of fuel fromfuel tanks. Many of these devices comprise an attachment portion toallow the device to be secured to a fuel tank and a body portion for thereceipt of fuel that, in use, extends inside the fuel tank (typically ofa vehicle). The body portion is of sufficient size to accommodate anozzle of a fuel delivery system. The body portion is typically providedwith holes through which the fuel may flow into the fuel tank. The holesare sufficiently small so as to inhibit passage therethrough of a hoseor the like for siphoning the fuel from the fuel tank. Such devices areoften prone to backflow; fuel is not transmitted sufficiently quicklythrough the holes into the device, causing a back-pressure which maycause the fuelling nozzle to temporarily cease fuelling or may causedischarge of fuel from the fuel tank either by welling or spitting; thisis obviously undesirable.

Devices have been modified in various ways in order to reduce orminimise the backflow problem. Some devices provide extra holes in thedevice; one device has no end wall, but rather a wedge-shaped memberthat allows passage therepast of fuel, but inhibits the passagetherepast of a siphon tube. The device of Blau provides an end wall witha wedge shape which urges fuel to the sidewalls of the device. Suchdevices still present backflow problems, at least at very high speeds offilling. Furthermore, there are other possible problems with these knowndevices in relation to fitting and security.

The object of the first aspect of the present invention is to overcomeor mitigate one or more of the above-mentioned problems.

In accordance with a first aspect of the present invention there isprovided a fuel tank inlet device for inhibiting theft of liquid fuelfrom a fuel tank, the device comprising an attachment portion adapted toallow the device to be secured to a fuel tank or filler neck thereof anda fuel inlet body portion for the receipt of fuel, the fuel inlet bodyportion comprising an inlet for the ingress of fuel and an outlet forthe egress of fuel into a fuel tank,

the fuel inlet body portion comprising a wall portion depending from afirst end of the device at or in the vicinity of the inlet to an endportion associated with a second end of the device,

the end portion having an inner surface for the receipt of fuel from anozzle and an outer surface,

wherein the outlet is provided by a plurality of bores in a part of thewall portion associated with the end portion and the inner surface ofthe end portion is shaped so as to direct fuel towards one or more ofsaid bores.

The device of the present invention provides for filling of fuel tanksat high flow rates whilst nonetheless securing against fuel theft.

The term “said bores” used hereafter refers to the plurality of bores inthe part of the wall portion associated with the end portion. Hence, theterm “at least one of said bores” refers to at least one of theplurality of bores in the part of the wall portion associated with theend portion. The term “said bores” does not refer to apertures or otherflow channels that may be found, for example, in the end portion.

The term “the part of the wall portion associated with the end portion”is that part of the wall portion that is in the vicinity of the endportion. Such a wall portion typically provides those flow channels thatare closest to the end portion. In use, said bores are generally thelowest flow channels through which fuel may flow.

The term “bore” is not limited to those fluid flow paths that may bemade by drilling or boring, and is not restricted to flow paths having agenerally cylindrical shape. It includes fluid flow paths of a moregeneral nature, such as those that may be made using milling. As such,the shape of the bore is not limited in any way, the bore permittingegress of fuel into the fuel tank from the inlet device.

It is preferred that the inner surface of the end portion is shaped soas to direct fuel towards the majority of said bores, and preferably allof said bores.

It is preferred that the inner surface of the end portion is inclinedtowards the wall portion. It is preferred that more than one (andoptionally each) of said bores faces a part of the inner surface of theend portion and that each of said parts is inclined towards thecorresponding bore.

It is preferred that the inner surface of the end portion is providedwith a surface of revolution for directing fuel towards one or more ofsaid bores. A surface of revolution is a surface that may be generatedby rotating a two-dimensional curve (the term “curve” including astraight line) about an axis. Such surfaces of revolution may, forexample, be conical, frusto-conical, horn shaped (for example, Gabriel'shorn) or paraboloid. The axis of revolution of the surface of revolutionmay be coincident with the longitudinal axis of the device.

The inner surface of the end portion is preferably provided with aconical, frusto-conical, pyramidal or frusto-pyramidal portion fordirecting fuel towards one or more of said bores. The sides of theconical, frusto-conical, pyramidal or frusto-pyramidal portion may beconvex, concave or preferably straight. Such an arrangement provides aneffective mechanism for facilitating the egress of fuel from the deviceinto the fuel tank. “Pyramidal” means a shape having a polygonal baseand triangular sides extending to an apex. Examples of such shapes are atetrahedron and the classic four-sided, square based pyramidal shape ofthe ancient Egyptian pyramids. “Frusto-pyramidal” refers to a truncatedpyramidal shape in the same way as “frusto-conical” refers to “conical”.The conical, frusto-conical, pyramidal or frusto-pyramidal surfaces donot have to be azimuthally symmetrical; for example, a conical surfacemay not be a surface of revolution.

At least one (and preferably a plurality) of said bores may be adjacentto, or extend to, said end portion. The location of said bores adjacentto, or extending to, the end portion facilitates fast flow of fuel fromthe device to the fuel tank.

The outlet may be further provided by a plurality of apertures in theend portion. Apertures in the end portion further facilitate fuel flowfrom the device to the fuel tank. The outlet may further be provided bya plurality of apertures in the wall portion in addition to said boresprovided in that part of the wall portion proximate to the end portion.Said apertures are, in use, above the part of the wall portion inproximity to the end portion. Said apertures assist in removing fuelfrom the device.

One or more (and preferably each) of said bores may extend from a boreinlet for the receipt of fuel from a nozzle to a bore outlet for theegress of fuel. The bore outlet may have a greater cross-sectional areathan the corresponding bore inlet.

The cross-sectional area of said bore may increase continuously from thebore inlet to the corresponding bore outlet. Such flared bores decreasethe resistance to flow of liquid compared to a conventional bore wherethe cross-sectional area at the bore inlet is the same as at the boreoutlet.

It is preferred that one or more (and preferably each) of said boresdefines a bore surface in the wall portion. The bore surface is boundedby the bore inlet and the bore outlet. It is preferred that, in use, thebore surface has a lower bore surface portion and an upper bore surfaceportion. The lower bore surface portion may extend, in use, downwardlyfrom the bore inlet to the bore outlet. In this case, the lower portionof the bore outlet is lower, in use, than the lower portion of the boreinlet. Such an arrangement aids fast egress of fuel from the inletdevice.

It is preferred that the inner surface of the end portion is providedwith a single (i.e. only one) surface of revolution for directing fuelto said bores, or a single conical, frusto-conical, pyramidal orfrusto-pyramidal portion. This provides an effective structure forfacilitating the egress of fuel from the device to the fuel tank.

The end portion is preferably provided with a border region between thewall portion and the said surface of revolution or conical, pyramidal,frusto-conical or frusto-pyramidal portion. This facilitates a simplemanufacturing process. The border region is preferably provided aroundthe perimeter of said surface of revolution, the conical, pyramidal,frusto-conical or frusto-pyramidal portion. The border region may have awidth of from 0.5 to 5 mm, and more preferably from 1 to 3 mm.

In the event that the end portion is provided with a conical orfrusto-conical portion, it is preferred that the angle at the apex (orprojected apex for a frusto-conical shape) as defined by θ=2 tan⁻¹(d/2h) is from 90 to 140 degrees, and preferably from 100 to 120degrees, where “d” is the diameter of the base of the cone and “h” isthe height of the cone (or projected height of the cone in the case of afrusto-conical shape). In the event that the end portion is providedwith a pyramidal or frusto-pyramidal region, the angle between a face ofthe pyramid and the adjacent wall portion may be from 45 to 70 degreesand preferably from 50 to 60 degrees.

It is preferred that the outer surface of the end portion is shaped tocorrespond to the shape of the inner surface of the end portion. Forexample, if the inner surface of the end portion is substantiallyconical, it is preferred that the outer surface of the end portion has asimilar conical shape. In this manner, the thickness of the end portionmay be reduced; this is advantageous is helping to reduce backflow.

It is preferred at least one of said bores is provided with a blockingmember for inhibiting ingress of a siphon tube into the fuel tank.

It is preferred that more than one (and more preferably each) of saidbores is provided with a blocking member. It is preferred that each ofsaid bores that is provided with a blocking member is associated withthe same blocking member.

It is preferred that the device is provided with a single (i.e. onlyone) blocking member.

At least one of the blocking members may be readily removable. It isfurther preferred that at least one of the of the blocking members maybe readily reattachable to the device.

It is preferred that at least one of the blocking members is resilientlydeformable. This facilitates the removal from, and reattachment to, thedevice.

It is preferred that at least one blocking member abuts against theouter surface of the wall portion. Such an arrangement is effective infacilitating the egress of fuel into the fuel tank. The location of theblocking member against the outer surface of the wall portion iseffective in permitting egress of fuel into the fuel tank. The outersurface of the wall portion may be provided with a recess for receivingthe blocking member.

Such an arrangement is effective in securely locating a blocking member.

At least one blocking member may be arcuate. It is preferred that atleast one blocking member is annular. It is preferred that said blockingmember comprises a split ring.

It is preferred that the attachment portion and the body portion areintegrally formed. The attachment portion and body portion may bemachined from a block of metal, such as aluminium.

Alternatively, the attachment portion may be formed separately from thewall portion. The wall portion may be formed from metal sheet.

The end portion may, at its thickest part, be from 2 mm to 20 mm thick,preferably from 2 mm to 10 mm thick and most preferably 5 mm to 8 mmthick.

The inlet device may be provided with a plurality of engagement members,each of which may be retracted from a first position in which eachengagement member abuts the filler neck or fuel tank so as to inhibitremoval of the device from a fuel tank to a second, retracted positionin which the device may be removed from the fuel tank.

Such a device may be fitted to a fuel tank without puncturing the fueltank or filler neck and may be removed from the fuel tank.

The attachment portion may comprise one or more lugs, such as those thatform a male part of a bayonet fitting. A bayonet fitting is a convenientway of attaching the device to the fuel tank because fuel tanks areoften provided with a fuel-cap receiving portion that comprises a femalepart of a bayonet fitting.

It is preferred that the end of each engagement member abuts against thefiller neck or fuel tank when in the first position.

It is preferred that, in the first position, the engagement membersextend laterally or radially from the body portion or the attachmentportion.

It is preferred that, in the first position, the engagement membersengage an inner surface of the fuel tank or filler neck.

The inlet device in the region of the engagement members may have aninside for the receipt of fuel from a fuel nozzle. It is preferred thatthe engagement members in the first position project outside the device.It is preferred that, in the second position, the engagement members areretracted at least partially inside the device. The engagement membersmay be accessible from the inside of the device so as to be movablebetween the first and second positions. The engagement members may beprovided with a configuration for the receipt of a tool (such as ahexagonal aperture or cross-shaped aperture).

It is preferred that at least one of the engagement members is elongate.

Each of the engagement members may be provided with a screw thread tofacilitate movement of the engagement member from the first position tothe second position.

It is preferred that one or more blanking members is provided to inhibitaccess to the engagement members when the engagement members are in thefirst position so as to inhibit the user from moving the engagementmember from the first position to the second position. Whilst it may bedesirable for the device to be removable from a fuel tank, it is oftendesirable to make removal difficult so that the device may not beremoved without effort. It is preferred that at least one blankingmember is provided on the inside of the device. It is preferred that atleast one blanking member inhibits access to the configuration for thereceipt of a tool (if such a configuration is provided on the engagementmembers).

It is preferred that one blanking member is associated with a pluralityand preferably all of the engagement members. In this latter case, oneblanking member inhibits access to all engagement members.

It is preferred that at least one of the blanking members is arcuate,and preferably annular or semi-annular. This provided a convenientgeometry for many devices.

It is preferred that at least one of the blanking members has an outersurface and an inner surface.

It is preferred that the inner surface of at least one blanking memberis, in use, substantially flush with an adjacent surface. It ispreferred that the outer surface of at least one blanking member isstepped. At least one blanking member may be provided with an upperportion and a lower portion, the maximum outer dimension of the upperportion being greater than that of the lower portion. This isparticularly effective when the blanking member is annular.

It is preferred that at least blanking member frictionally engages witha surface of the fuel inlet body portion or the attachment portion toresist removal of the at least one blanking member. This resists removalof the blanking member from the fuel inlet body portion or theattachment portion.

It is preferred that at least one blanking member is a tamper-evidentblanking member. At least one blanking member may be frangible orreadily plastically deformable. This is so that attempting to remove theblanking member may cause it to break, for example, by being plasticallydeformed into a folded configuration. The deformed or broken blankingmember cannot subsequently be placed back in position in the device, andit is therefore evident that the device has been tampered with.

The wall portion may provide a convenient tubular structure. The wallportion may be generally cylindrical in shape. Examples of such shapesinclude a right circular cylindrical shape or a square-sectioncylindrical shape.

There are many conventional methods for securing an anti-theft fuelinlet device to a fuel tank or filler neck so as to resist removal ofthe device. One such method is by using fixtures that penetrate the fueltank or filler neck; this is obviously undesirable because the holesmade by such fittings may allow potentially dangerous fuel to escapefrom the fuel tank, even when the holes are “filled” with rivets or thelike. Escape of fuel from fuel tanks may allow fuel to seep onto roadscausing a slip hazard. Puncturing the tank also potentially renders thetank more vulnerable to larger-scale leakage in the event of accidentswhen rivets or other such fittings may snap or loosen, leaving a clearchannel for leakage. Another method is to use some form of adhesive.Such adhesives may permanently attach the device to the fuel tank andthis may not be desired. Furthermore, if the device is removed, residuesof adhesive may be left on the device and/or tank which require removal.Many adhesives also take a considerable time to cure and a fuel tankshould not be fuelled until curing is complete. Adhesives may degrade intime to produce an imperfect seal. Furthermore, even very strongadhesives do not typically resist removal by a twisting action, as maybe imparted using a stilson tool or large spanner as a lever. Adhesivestypically require each surface to be adhered to be very clean. It isalso difficult to assess how much adhesive to use; too little or toomuch adhesive may cause problems.

Several methods have been proposed to overcome the problems ofpuncturing the fuel tank or using adhesive. One such device uses aspring-loaded wedge that allows a device with a bayonet fitting to beturned into place, but does not allow the device to be readily removed.This device also has barbs that inhibit removal of the device. Suchbarbs are designed to either prevent removal of the device or wouldapparently be broken or at least damaged if the device is removed.

The fuel tank inlet device of the second aspect of the present inventionseeks to overcome or mitigate against at least one of the problemspresented in the prior art.

In accordance with the second aspect of the present invention there isprovided a fuel tank inlet device for inhibiting theft of liquid fuelfrom a fuel tank, the device comprising a fuel inlet body portion forthe receipt of fuel, the fuel inlet body portion comprising an inlet forthe ingress of fuel and an outlet for the egress of fuel into a fueltank,

the inlet device being provided with a plurality of engagement members,each of which may be retracted from a first position in which eachengagement member abuts the filler neck or fuel tank so as to inhibitremoval of device from fuel tank to a second, retracted position inwhich the device may be removed from the fuel tank.

Such a device may be fitted to a fuel tank without puncturing the fueltank or filler neck and may be removed from the fuel tank.

The device may comprise an attachment portion adapted to allow thedevice to be secured to a fuel tank or filler neck thereof.

The attachment portion may comprise one or more lugs, such as those thatform a male part of a bayonet fitting. A bayonet fitting is a convenientway of attaching the device to the fuel tank because fuel tanks areoften provided with a fuel-cap receiving portion that comprises a femalepart of a bayonet fitting.

It is preferred that, in the first position, the engagement membersextend laterally or radially from the fuel inlet body portion or theattachment portion.

It is preferred that, in the first position, each engagement member (andpreferably the end thereof) abuts an inner surface of the fuel tank orfiller neck.

The inlet device in the region of the engagement members may have aninside for the receipt of fuel from a fuel nozzle. It is preferred thatthe engagement members in the first position project outside the device.It is preferred that, in the second position, the engagement members areretracted at least partially inside the device. The engagement membersmay be accessible from the inside of the device so as to be movablebetween the first and second positions. The engagement members may beprovided with a configuration for the receipt of a tool (such as ahexagonal or cross-shaped aperture).

It is preferred that each of the engagement members is elongate.

Each of the engagement members may be provided with a screw thread tofacilitate movement of the engagement member from the first position tothe second position.

It is preferred that one or more blanking members is provided to inhibitaccess to the engagement members when the engagement members are in thefirst position so as to inhibit the user from moving the engagementmember from the first position to the second position. Whilst it may bedesirable for the device to be removable from a fuel tank, it is oftendesirable to make removal difficult so that the device may not beremoved without effort, suitable tools and skill. It is preferred thatat least one blanking member is provided on the inside of the device. Itis further preferred that at least one blanking member inhibits accessto the configuration for the receipt of a tool (if such a configurationis provided on the engagement members).

It is preferred that one blanking member is associated with a pluralityand preferably all of the engagement members. In this latter case, oneblanking member inhibits access to all engagement members.

It is preferred that at least one of the blanking members is arcuate,and preferably annular or semi-annular. This provided a convenientgeometry for many devices.

It is preferred that at least one of the blanking members has an outersurface and an inner surface.

It is preferred that the inner surface of at least one blanking memberis, in use, substantially flush with an adjacent surface. It ispreferred that the outer surface of at least one blanking member isstepped. At least one blanking member may be provided with an upperportion, and a lower portion, the maximum outer dimension of the upperportion being greater than that of the lower portion. This isparticularly effective when the blanking member is annular.

It is preferred that at least one blanking member frictionally engageswith a surface of the fuel inlet body portion or the attachment portionto resist removal of the at least one blanking member. This resistsremoval of the blanking member from the fuel inlet body portion.

It is preferred that at least one blanking member is a tamper-evidentblanking member. At least one blanking member may be frangible orreadily plastically deformable. This is so that attempting to remove theblanking member may cause it to break, for example, by being plasticallydeformed into a folded configuration. The deformed or broken blankingmember cannot subsequently placed back in position in the device, and itis therefore evident that the device has been tampered with.

The fuel inlet body portion may comprise a wall portion depending from afirst end of the device at or in the vicinity of the inlet to an endportion associated with a second end of the device,

the end portion having an inner surface for the receipt of fuel from anozzle and an outer surface,

wherein the outlet is provided by a plurality of bores in the region ofthe wall portion associated with the end portion and the inner surfaceof the end portion is shaped so as to direct fuel towards one or more ofsaid bores.

This provides a convenient arrangement for facilitating the rapid egressof fuel from the inlet device to the fuel tank.

The fuel inlet device of the second aspect of the present invention maycomprise those features described above in relation to the fuel inletdevice of the first aspect of the present invention. For example, theinner surface of the end portion may be provided with a surface ofrevolution or a conical, frusto-conical, pyramidal or frusto-pyramidalportion for directing fuel to said bores.

The inlet device of the present invention will now be described withreference to the following figures of which:

FIG. 1 is a schematic side-on view of an embodiment of a device inaccordance with the present invention;

FIG. 2 is a schematic cross-section through the device of FIG. 1;

FIG. 3 is an view of a portion of the device of FIG. 1 showinggrub-screws that are used to inhibit unwanted removal of the device andthe blanking member that is used to inhibit access to the screws;

FIG. 4 a shows a perspective view of one of said bores in the part ofthe wall portion associated with the end portion; and

FIG. 4 b shows a cross-sectional view through said bore of FIG. 4 a.

FIGS. 1 and 2 show a side-on view and a cross-sectional viewrespectively of an embodiment of an inlet device in accordance with thepresent invention, wherein the inner surface of the end portion of thedevice is provided with a conical portion for directing the fuel to thewall portion. The fuel tank inlet device is shown generally by referencenumeral 1 and inhibits theft of liquid fuel from a fuel tank to whichthe device is attached. The device 1 comprises an attachment portionshown generally by reference numeral 2 adapted to allow the device 1 tobe secured to a fuel tank or filler neck thereof, a fuel inlet bodyportion shown generally by the reference numeral 5 for the receipt offuel, the fuel inlet body portion 5 comprising an inlet 12 for theingress of fuel and an outlet for the egress of fuel into a fuel tank.The fuel inlet body portion 5 comprises a wall portion 7 depending froma first end of the device associated with the inlet 12 to an end portion9 associated with a second end of the device 1. The end portion 9 has aninner surface 9 a associated with the receipt of fuel from a nozzle andan outer surface 9 b associated, in use, with a fuel tank, and the innersurface 9 a of the end portion 9 is shaped so as to direct fuel towardsbores (exemplified by reference numerals 10 a-e) in the part 21 of thewall portion 7 associated with the end portion 9.

The device 1 is generally made from aluminium and may essentially bemade by machining from a single block of metal. This enables the deviceto be made easily and cheaply. The fuel inlet body portion 5 is of agenerally tubular form, having an inner surface 22 associated with thereceipt of fuel from a nozzle and an outer surface 23 that is, in use,associated with a fuel tank. The inner 22 and outer 23 surfaces areseparated by a cylindrical wall portion 7 forming the sides of the fuelinlet body portion and an end portion or end wall 9 at the end of thefuel inlet body portion 5 remote from the inlet 12. The cylindrical wallis generally about 7 mm thick. Holes 6 are provided to allow fumes tovent from the device.

The end portion is typically around 7 mm thick. Such a thickness resistsphysical damage to the end portion 9 that may be caused by trying toforce a bar or rigid object through the end portion so that a siphontube may be inserted through a damaged device into the fuel tank. Theouter surface 9 b of the end portion is shaped to correspond to theinner surface 9 a of the end portion i.e. the outer surface 9 b is alsoprovided with a conical portion. This arrangement ensures that thethickness of the end portion is large enough to resist attack but thinenough to permit fuel to egress into the fuel tank at a desired rate. Ithas been found that if the outer surface is not so shaped (for exampleif the outer surface is flat) then the fluid flow path through the endportion itself is longer, resulting is potentially unacceptable backflow.

Apertures are provided in the end portion 9 and are exemplified byreference numerals 14. The apertures 14 are provided to permit egress offuel from the device. The apertures 14 extend from the inner surface 9 ato the outer surface 9 b of the end portion 9, and are substantiallyparallel to the longitudinal axis of the device.

Apertures (exemplified by reference numeral 8) are provided in theregion of the wall portion 7 above the end portion 9. These aperturesare elongate, the long axis of each aperture being substantiallyparallel to the longitudinal axis of the device 1. Such geometry iseffective at facilitating fast egress of fuel into the fuel tank. Theend portion 9 does not direct fuel to apertures 8.

Said bores exemplified by reference numerals 10 a-e are in the lowerpart 21 of the wall portion, proximate to the end portion 9. The innersurface 9 a of end portion 9 is provided with a conical portion which isreadily visible in FIG. 2. The angle θ (as shown in FIG. 2) is about 110degrees. The conical shape directs incoming fuel towards said bores 10a-e formed in part 21 of the wall portion 7 proximate to the end portion9. The geometry of each of said bores 10 a-e is shown in more detail inFIGS. 4 a and 4 b. FIG. 4 b is a cross-sectional view taken throughplane O-O of said bore shown in perspective in FIG. 4 a. Each bore isprovided with a bore inlet 18 associated with the inner surface 22 ofthe wall portion and a bore outlet 19 associated with the outer surface23 of the wall portion 7. In use, a fuel nozzle is inserted into thefuel inlet device and fuel is discharged into the device and out intothe fuel tank through said bores 10 a-e. The fuel enters the bore inlet18, passes through the bore and into the fuel tank via the bore outlet19. The cross-sectional area of the bore outlet 19 is greater than thebore inlet 18 and this helps prevent backflow in the device.Furthermore, referring to FIG. 4, the bore surface 20 comprises an upperportion 20 b and a lower portion 20 a. The lower portion 20 a extendsdownwardly from the bore inlet 18 to the bore outlet 19. This also helpsinhibit backflow in the device. The angle, α, is about 45 degrees.

Referring to FIGS. 1 and 2, a blocking member 11 in the form of a splitring is provided for all of said bores 10 a-e in the part 21 of the wallportion 7 associated with the end portion 9. The blocking member 11 islocated in a recess formed in the outer surface 23 of the wall portion7. The blocking member inhibits passage of a siphon tube through saidbores 10 a-e. Furthermore, by being placed on the outer surface of thedevice, the resistance to flow is less than if it was placed on theinner surface of the device. Such a removable and replaceable blockingmember is readily available and simple to fit. The blocking member isrelatively narrow having a width of about 1-2 mm or so; a thin blockingmember does not significantly inhibit egress of fuel from the device,but inhibits ingress into the fuel tank of a siphon tube. A blockingmember that is integral with the wall portion could be used, butmanufacture of a narrow, integral blocking member would be difficult andexpensive. The blocking member 11 has been omitted from FIGS. 4 a and 4b for the purpose of clarity.

Referring to FIGS. 1, 2 and 3, the device 1 is provided with a pluralityof engagement members 4 a-c, each of which may be retracted from (i) afirst position in which an end of each engagement member engages thefiller neck or fuel tank, so as to inhibit removal of device from fueltank to (ii) a second, retracted position in which the device may beremoved from the fuel tank. In each of FIGS. 1, 2 and 3 the engagementmembers 4 a-c (in this case, grub screws) are in the first position. Inthis position, the ends of the grub screws engage with the inner surfaceof the filler neck of a fuel tank. This engagement inhibits removal ofthe device from the fuel tank. A blanking member 15 is provided toinhibit access to the engagement members 4 a-c. FIG. 2 shows theblanking member 15 in position. FIG. 3 is a partially exploded view withthe blanking member 15 removed from the device in order to show itsshape. Note that only a part of the device is shown in FIG. 3 for thepurpose of clarity. The blanking member is annular in shape (see FIG. 3)and has an upper portion 15 a that has a larger external diameter than alower portion 15 b. The blanking member 15 is friction-fitted into placein the fuel inlet body portion 5 so as to be difficult to removetherefrom. Contrary to the suggestion of FIG. 2, the inner surface ofthe blanking member 15 is flush with the inner surface 22 of the fuelinlet body portion. The three engagement members 4 a-c are spacedequidistantly around the circumference of the fuel inlet body portion 5.

In order to remove the device 1 from a fuel tank, the blanking member 15is removed using a sharp-edged or bladed instrument, such as a chisel.The blade of the chisel is placed against the edge of the blankingmember and the chisel hit hard. This causes the breakage or moretypically the plastic deformation of the blanking member. The blankingmember cannot be put back into the device. This provides a blankingmember that is tamper-evident. The blanking member is made of aluminiumand is readily plastically deformable.

The ends of the engagement members 4 a-c (formerly covered by theblanking member 15) are provided with a slot or hexagonal recess for thereceipt of a suitable removal tool. The engagement members 4 a-c maythen be accessed from the inside 16 of the device 1 and may be movedinto a retracted position in which the ends of the engagement members 4a-c do not engage with the filler pipe and thus the device 1 may beremoved from the fuel tank.

In order to install the device 1, the engagement members would beretracted, the device located in place by inserting the lugs 3 a,b inthe appropriate groove in the filler neck or in a fitment used toreceive a filler cap (such a fitment having a female part of a bayonetfitting). The device would then be rotated to urge the lugs into alocking position. An appropriate tool (such as an Allen key or ascrewdriver) would then be used to move the engagement members 4 a-cinto the first position in which the end of each engagement member 4 a-cengage with the filler neck of the fuel tank. Once the engagementmembers 4 a-c are in the first position the blanking member 15 is urgedinto place (see FIG. 2).

1. A fuel tank inlet device for inhibiting theft of liquid fuel from afuel tank, the device comprising an attachment portion adapted to allowthe device to be secured to a fuel tank or filler neck thereof and afuel inlet body portion for the receipt of fuel, the fuel inlet bodyportion comprising an inlet for the ingress of fuel and an outlet forthe egress of fuel into a fuel tank, the fuel inlet body portioncomprising a wall portion depending from a first end of the device at orin the vicinity of the inlet to an end portion associated with a secondend of the device, the end portion having an inner surface for thereceipt of fuel from a nozzle and an outer surface, the outlet beingprovided by a plurality of bores in a part of the wall portionassociated with the end portion and the inner surface of the end portionbeing shaped so as to direct fuel towards one or more of said bores, theinner surface of the end portion being provided with a surface ofrevolution for directing fuel towards one or more of said bores, one ormore of said bores extending from a bore inlet for the receipt of fuelfrom a nozzle to a bore outlet for the egress of fuel, wherein the boreoutlet has a greater cross-sectional area than the corresponding boreinlet.
 2. A fuel tank inlet device according to claim 1 wherein thesurface of revolution comprises a conical, frusto-conical, paraboloidalor horn-shaped portion for directing fuel towards one or more of saidbores.
 3. A fuel tank inlet device according to claim 1 wherein at leastone of said bores is adjacent to, or extends to, said end portion.
 4. Afuel tank inlet device according to claim 1, wherein each bore inlet andbore outlet bounds a bore surface in the wall portion, the bore surface,in use, having a lower bore surface portion and an upper bore surfaceportion, wherein the lower bore surface portion extends downwardly fromthe bore inlet to the bore outlet. 5-6. (canceled)
 7. A fuel tank inletdevice according to claim 1, the device being provided with a singleblocking member to inhibit ingress of a siphon tube into the fuel tank,wherein at least one of said bores is associated with the blockingmember so that ingress of a siphon tube through at least one of saidbores is inhibited by the blocking member.
 8. (canceled)
 9. A fuel tankinlet device according to claim 1, the device being provided with asingle blocking member to inhibit ingress of a siphon tube into the fueltank, wherein at least one of said bores is associated with the blockingmember so that ingress of a siphon tube through at least one of saidbores is associated with one of said blocking members so that ingress ofa siphon tube through at least one of said bores is inhibited by one ofsaid blocking members.
 10. (canceled)
 11. A fuel tank inlet deviceaccording to claim 1, the device being provided with a single blockingmember to inhibit ingress of a siphon tube into the fuel tank, whereinat least one of said bores is associated with the blocking member sothat ingress of a siphon tube through at least one of said bores isinhibited by the blocking member.
 12. (canceled)
 13. A fuel tank inletdevice according to claim 1, the device being provided with a singleblocking member to inhibit ingress of a siphon tube into the fuel tank,wherein at least one of said bores is associated with the blockingmember so that ingress of a siphon tube through at least one of saidbores is inhibited by the blocking member and wherein the blockingmember is resiliently deformable.
 14. A fuel inlet tank device accordingto claim 1, the device being provided with a single blocking member toinhibit ingress of a siphon tube into the fuel tank, wherein at leastone of said bores is associated with the blocking member so that ingressof a siphon tube through at least one of said bores is inhibited by theblocking member and wherein the blocking member abuts against the outersurface of the wall portion, the blocking member being received in arecess provided in the outer surface of the wall portion.
 15. (canceled)16. A fuel tank inlet device according to claim 1, further comprising aplurality of engagement members, each of which may be retracted from afirst position in which the engagement member abuts a filler neck orfuel tank so as to inhibit removal of device from fuel tank to a second,retracted position in which the device may be removed from the fueltank.
 17. A fuel tank inlet device according to claim 1, furthercomprising a plurality of engagement members, each of which may beretracted from a first position in which the engagement member abuts afiller neck or fuel tank so as to inhibit removal of device from fueltank to a second, retracted position in which the device may be removedfrom the fuel tank, wherein, in the first position, each engagementmember abuts an inner surface of the fuel tank or filler neck.
 18. Afuel tank inlet device according to claim 1, further comprising aplurality of engagement members, each of which may be retracted from afirst position in which the engagement member abuts a filler neck orfuel tank so as to inhibit removal of device from fuel tank to a second,retracted position in which the device may be removed from the fueltank, wherein the inlet device in the region of the engagement membershas an inside for the receipt of fuel from a fuel nozzle, the engagementmembers in the first position projecting outside the device, wherein thesecond position the engagement members are retracted at least partiallyinside the device.
 19. (canceled)
 20. A fuel tank inlet device accordingto claim 1, further comprising a plurality of engagement members, eachof which may be retracted from a first position in which the engagementmember abuts a filler neck or fuel tank so as to inhibit removal ofdevice from fuel tank to a second, retracted position in which thedevice may be removed from the fuel tank, wherein the inlet device inthe region of the engagement members has an inside for the receipt offuel from a fuel nozzle, the engagement members in the first positionprojecting outside the device, wherein in the second position theengagement members are retracted at least partially inside the deviceand wherein the engagement members are accessible from the inside of thedevice so as to be movable between the first and second positions. 21.(canceled)
 22. A fuel inlet tank device according to claim 1, furthercomprising a plurality of engagement members, each of which may beretracted from a first position in which the engagement member abuts afiller neck or fuel tank so as to inhibit removal of device from fueltank to a second, retracted position in which the device may be removedfrom the fuel tank, the device being further provided with one or moreblanking members for inhibiting access to the engagement members whenthe engagement members are in the first position so as to inhibit theuser from moving the engagement member from the first position to thesecond position, wherein the one or more blanking members are frangibleor readily plastically deformable.
 23. A fuel inlet tank deviceaccording to claim 1, further comprising a plurality of engagementmembers, each of which may be retracted from a first position in whichthe engagement member abuts a filler neck or fuel tank so as to inhibitremoval of device from fuel tank to a second, retracted position inwhich the device may be removed from the fuel tank, the device beingfurther provided with a single blanking member for inhibiting access toall of the engagement members when the engagement members are in thefirst position so as to inhibit the user from moving the engagementmember from the first position to the second position, wherein theblanking member is frangible or readily plastically deformable.
 24. Afuel tank inlet device according to claim 1, further comprising aplurality of engagement members, each of which may be retracted from afirst position in which the engagement member abuts a filler neck orfuel tank so as to inhibit removal of device from fuel tank to a second,retracted position in which the device may be removed from the fueltank, the device being further provided with one or more blankingmembers for inhibiting access to the engagement members when theengagement members are in the first position so as to inhibit the userfrom moving the engagement member from the first position to the secondposition, wherein the one or more blanking members are frangible orreadily plastically deformable and at least one blanketing member is, inuse, provided on the inside of the device. 25-28. (canceled)
 29. A fuelinlet tank device according to claim 1, further comprising a pluralityof engagement members, each of which may be retracted from a firstposition in which the engagement member abuts a filler neck or fuel tankso as to inhibit removal of device from fuel tank to a second, retractedposition in which the device may be removed from the fuel tank, thedevice being further provided with one or more blanking members forinhibiting access to the engagement members when the engagement membersare in the first position so as to inhibit the user from moving theengagement member from the first position to the second position,wherein the one or more blanking members are frangible or readilyplastically deformable and at least one blanking member frictionallyengages with a surface of the fuel inlet body portion or the attachmentportion to resist removal of the at least one blanking member. 30-32.(canceled)
 33. A fuel inlet tank device for inhibiting theft of liquidfuel from a fuel tank, the device comprising a fuel inlet body portionfor the receipt of fuel, the fuel inlet body portion comprising an inletfor the ingress of fuel and an outlet for the egress of fuel into a fueltank, the inlet device being provided with a plurality of engagementmembers, each of which may be retracted from a first position in whicheach engagement member abuts a filler neck or fuel tank as to inhibitremoval of device from fuel tank to a second, retracted position inwhich the device may be removed from the fuel tank.
 34. A fuel tankinlet device according to claim 33 further provided with one or moreblanking members for inhibiting access to the engagement members whenthe engagement members are in the first position so as to inhibit theuser from moving the engagement member from the first position to thesecond position.
 35. A fuel tank inlet device according to claim 34wherein a single blanking member is associated with all of theengagement members.